Document from the year 2014 in the subject Chemistry - Organic Chemistry, grade: A-C, , language: English, abstract: Here we discuss the structure and synthesis of various Vitamins. Vitamin A influences growth in animals, and also apparently increases resistance to disease. Night blindness is due to vitamin A deficiency in the human diet, and a prolonged deficiency leads to hardening of the cornea, etc. Vitamin A occurs free and as esters in fats, in fish livers and in blood. It was originally isolated as viscous yellow oil, but later it was obtained as a crystalline solid, m.p. 63-64°C.